I don't know whether D can run on one, but from a quick look
perhaps feasible. Running D on something like this (perhaps it's
underpowered, but looked to have similar spec to what people had
been doing with related ARM cortex processors) would certainly
make the point very vivid that it can be a bare metal programming
language.
Only 1Mb of flash RAM for the program - is that enough?
https://learn.adafruit.com/dash-hacking-bare-metal-stm32-programming/programming
https://learn.adafruit.com/dash-hacking-bare-metal-stm32-programming/overview
The Amazon Dash button is a tiny device that orders products from
Amazon.com at the press of a button. It's designed to be put
wherever you store consumeables like paper towels, trash bags,
etc. so that you can easily order more when they run out. The
Dash is great at what it's designed to do, but did you know
inside the Dash is a powerful ARM Cortex-M3 processor and WiFi
module that are very similar to wireless development boards like
the Particle Photon? You'll even find there are easily
accessible test pads on the Dash which allow you to reprogram its
CPU and turn it into your own $5 internet button! This guide
will explore how to take apart the Dash and reprogram its CPU to
run your own code.
...
The CPU is a STM32F205RG6 processor which is an ARM Cortex-M3
that can run up to 120mhz and has 128 kilobytes of RAM and 1
megabyte of flash memory for program storage.
The WiFi module is a BCM943362 module which in combination with
the CPU make it a platform for Broadcom's WICED SDK.
There's a 16 megabit SPI flash ROM which is typically used in
conjunction with the WICED SDK for storing application data.
An ADMP441 microphone is connected to the CPU and used by the
Dash iOS application to configure the device using the speaker on
a phone/tablet.
There's a single RGB LED and a button.